c - How to get char array size in this case? -

i'm doubt: how size of char array in case:

#include<stdio.h>  void f(char * x) { printf("size %d\n", sizeof(x)/sizeof(char)); }  main() { char x[5] = {'a', 'e', 'i', 'o', 'u'}; f(&x[0]); } 

contrary expectations, i'm receiving 8 rather 5 or 6. wrong here?

thanks!

sizeof(x) in code return size of pointer char *x , not size of char array x pointing on

and size of pointer in 64-bits system 8. , 32-bits system size of pointer 4